DESCRIPTION (Taken from application) This proposal seeks to establish a Biostatistics Core (BC) Project to serve the individual research projects by providing statistical consulting, developing custom statistical methodologies, and by providing student training on principles of the experimental design and statistical methods in modern molecular biology. Research projects in this proposal are likely to require statistical assistance in designing experiments, including sample size calculations, and the statistical analysis of experimental data. Most of the statistical issues that will be encountered in the proposed research projects have been addressed by statistical theory and appropriate methods are implemented in available statistical software. Already existing methods will be applied whenever applicable. On the other hand, the analysis of the data that will be generated by some projects, such as mutational spectra and DNA microarrays data will require development of new statistical methodologies. In this respect the Biostatistics Core will develop statistical methods for investigating different aspects of DNA microarrays data. A method for establishing statistically significant differences in expression levels of individual genes as well as a method for classifying overall gene expression patterns will be developed. The BC will also develop a new classification system for predicting mechanism of action of a mutagen based on the mutational spectra it generates. Statistical training of students will be facilitated through a course that will be taught in the Epidemiology and Biostatistics Division of the Environmental Health Department. Finally, in addition to directly addressing statistical needs of research projects, BC will facilitate the interaction between program projects and other data analysis services within the University of Cincinnati when needed.